Integrated weed management in soybean (Glycine ma) under different moisture regimes and population densities

Abstract

A field experiment was conducted during summer and rainy seasons of 1994 at Coimbatore, to study the effects of weed-management methods with varying levels of plant densities under 2 irrigation moisture regimes on soybean [Glycine max (L.) Merr.]. Though the lowest moisture regime (0.40 IW : CPE) recorded better weed-control efficiency and decreased N uptake by weeds at harvest, the higher moisture regume (0.60 IW : CPE) enhanced the N uptake and crop dry- matter production. Weed-control efficiency was found higher at 666,000 plantst ha. Among the weed-management methods, alachlor 1.25 kglha + hand-weeding -- . 40 days after sowing recorded the highest weed-control efficiency and was as good as hand-weeding twice. An increase in yield of the crop as well as the net return was registered under higher moisture regime of 0.60 IW : CPE ratio. The - density of 444,000 plantstha markedly increased the yield in summer, whereas it was comparable with 666,000 plantstha during the rainy season.